建筑结构用高性能Q460GJD钢全位置焊接技术

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Abstract： In the Guangshang Center super-high-rise building project，facing the technicalchallenge of welding Q460GJD steel high-performance thick plate （ 100mm ）rectangular tube components of the ring truss in all positions athighaltitudeon-site，conducted a systematic welding technology research.Q46oGJD steel hasa high carbon equivalent （≈0.50%） ）anda strong tendency to harden，which can easily lead to embritlement of the heat-affected Zone and cold cracking during welding.Furthermore，controlling residual stressand deformation in thick plate welding is extremely dificult. Through weldability analysis，determined the use of ER55-G welding wire and Ar+ CO2 mixed shielding gas for gas metal arc welding （GMAW）. A full-processquality control system was developed， covering preheating before welding， Strict interlayer temperature control， multi-layer and multi-ass welding proceses，and post-weld heat treatment.Focuse on the welding parameters and key operating points for three typical positions：horizontal，vertical，andoverhead.Special measures，uchasasymmetrical welding sequence，fectively control welding deformation.The project practice results show that this technical solution successully solved the problem of all-position welding of Q460GJD steel thick plates，and the one-time pass rate of welds was extremely high，providing important theoretical support and practical basis for the welding construction of similar highperformance steels under complex working conditions.

Keywords：high-performance steel; all position welding;Q46oGJD steel

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广商中心项目是一座设计高度达 375.50m 的全钢结构超高层建筑，该项目占地面积 6909m2 ，地上60层，地下5层，总建筑面积 207014m2 ，其结构体系创新性地采用了无钢筋混凝土核心筒的巨型框架支撑体系。（剩余4230字）